This invention relates to an apparatus for detecting foreign bodies such as foreign fibers, tying strings, bands of synthetic material, wire pieces and the like within or between textile fiber tufts, particularly cotton and/or synthetic fiber tufts.
In practice undesirable foreign fiber materials may be found within a cotton or synthetic fiber mass which, to a significant degree, adversely affect the making of high quality yarns. The foreign fiber material frequently remains in the mass of useful fibers after processing in the cleaning and spinning installations and, among others, disadvantageously leads to colorings. In many instances, the impurities are jute, kemp or polypropylene strings or bands. The foreign fibers originate mostly from packaging and from sacks which had been utilized during harvest.
Foreign fibers, tying strings or the like can be found in practice frequently in the pressed fiber bales. The pressed-in strings extend often through several layers (zones) so that it is frequently necessary to manually dig deeply into the bales for removing the entire string or band. Proceeding in this manner is very time-consuming and adversely affects the continuous fiber processing.